Pressure tube salvage apparatus and method



March 28, 1967 D. HENDRY PRESSURE TUBE SALVAGE APPARATUS AND METHODFiled May '7, 1965 GILBERT o. HENDRY. ATTORNEY United States Patent3,311,078 PRESSURE TUBE SALVAGE APPARATUS AND METHOD Gilbert 1). Hendry,35 Burcrest Drive, Toronto, Ontario, Canada Filed May 7, 1965, Ser. No.453,987 7 Claims. (Cl. 11450) This invention relates to the salvage orrefloating of sunken vessels and is specifically directed to a novelmethod and apparatus whereby the stability and ascent of a vessel duringthe refioating process may be more readily and accurately controlledthan heretofore possible.

Many proposals have been put forth and tested respecting theintroduction of compressed air or foamant material into the hull of asunken ship but while such proposed expedients have achieved a degree ofsuccess, major problems still exist in their use.

One of the aforementioned problems resides in containing the compressedair or foamant in the vessel and in order to preclude escape of thelatter, extremely expensive and frequently difficult underwaterpreparatory work is required to seal hatches, ventilators and damagedareas. In instances where a ship has gone down in deep water, divingoperations are limited and are often rendered hazardous by tricky andpowerful currents. All this adds up to very high costs with limitedguarantee of eventual success.

In an attempt to overcome the problems faced in completely sealing theship, inflatable containers have been and are being used to contain thebuoyant agent. These containers, usually provided with an outerprotective mesh covering are located within the ship and then compressedair or foamant is pumped in. At first blush, this appeared to be asolution but it has been found that a high percentage of the containersare ruptured in use, either by projections within the ship or bypressure differential unbalance as the ship rises through the varyingpressure levels of the surrounding water. As the flexible containers arequite expensive, it is obvious that this solution is not entirelysatisfactory.

It has further been proposed to pump liquid foamants into the hull of asunken vessel such that they commence to foam within the hull. Hereagain, the problem of extensive under-water preparation to preventescape of the liquid foamant prior to complete formation of the foamstructure is encountered.

With these prior art methods there has also prevailed the difficulty ofensuring that the ship rises in a stable manner, that is, the ship doesnot tend to roll or pitch about its longitudinal or lateral axes. It isof course, almost impossible to completely seal the hull of a sunkenship, especially when the latter has been damaged to any extent and thussalvage operators on the surface have no way of deter-mining Whether ornot the buoyancy forces exerted on a ship are evenly distributed at anygiven time. Until such time as the ship has risen to a critical level,there can be little or no lift or attitude control exercised. By thetime the situation becomes apparent, there is only a very limited timeto effect some form of stabilizing action before the ship rolls orpitches over. In short, use of compressed air or materials difficult tocontain are unpredictable and have generally been found unsatisfactoryin salvage attempts.

It is an object of this invention to provide a novel salvage method andapparatus which minimizes preparatory under water work thus considerablyfacilitating the salvage of vessels, especially those lying in deepwater and subject to strong currents.

It is a further object of this invention to provide a novel salvagemethod and apparatus wherein the buoyant materials may be recovered forre-use.

A still further object is to provide a salvage method and apparatuswherein control of the ships attitude during its ascent is morepredictable than in presently known methods.

The foregoing objects are achieved by driving bundles or charges ofsolid buoyant material into the ship such that hatchways and otheropenings merely require the placement of perforate grids thereover inorder to preclude escape of the charges. It will be readily apparentthat such grids may be handled under water with far greater facilitythan large, heavy patch plates and the like.

In order to ensure more or less even distribution of the charges withinthe ship, water jets may be employed to create turbulence in the shipsinterior. Further, any undamaged ballast tanks or the like may bepartially blown or evacuated to a degree to a degree dependent upon theparticular ships attitude, area of damage and The invention will be morereadily understood from the following detailed description taken inconjunction with the appended drawings wherein:

FIGURE 1, A schematic representation of the tube means assembled and inoperative position with respect to a salvage vessel and a sunken ship.

FIGURE 2, An enlarged view of the pump and feed sections of the tubemeans and FIGURE 3, A detail of the gate actuating means.

As previously noted, one of the prime advantages of this inventionresides in the substantial savings obtained in underwater preparation ofthe vessel prior to the actual operation of inserting the buoyantmaterial.

In some instances it will be found possible to lower prefabricated grillstructures into position over hatches and other openings for welding orotherwise securing thereto. Such grills may be of coarse mesh, theopenings therein being of a size sufficient to just preclude escape ofthe charges of buoyant material.

In other situations, suitable lengths of structural steel members may belowered into position over any openings or weak-spots such as hatchesetc. and secured in a charge-confining arrangement by any of thewellknown expedients.

Generally speaking, the installation of the charge-retaining structureand the type or system to be used will be ascertained following a studyof the type of vessel involved, the depth of water and the currentsinvolved. Naturally, conditions will vary considerably from case to caseand it is considered unnecessary to enter into a prolonged discussionherein concerning this point. To those skilled in this field, theappropriate steps necessary in any given situation to affix the requiredgrills in position will be readily apparent.

A further important consideration is the type of bu0yant material to beused. In many instances, the selection will be affected by the salvagelocation and availability of materials, however with this novel methodand apparatus, considerable latitude is granted. Generally, any more orless solid, buoyant material may be used. In each case, the material iscut to form packages or charges of a size governed only by thedimensions of the delivery tube and handling considerations on board thesalvage ship together with the effects of charge size upon distributionwithin the sunken vessel.

It will be appreciated that the materials used herein are also salvagedwith the ship and may be used again whereas with most prior salvagemethods, the materials are not only useless for re-application infurther salvage work but also for any other purpose. This instantinvention is thus seen to present considerable savings as regardspreliminary driving operations and as regards the cost of material.

. ram 22.

11 and the salvage vessel 12 may comprise some form ofchain or likeconveyor means suitable for feeding buoyant material from the salvagevessel to the said loading deck. Such a flexible connection isolates thetube means from undesirable movement of the ship.

It is also feasible that in sheltered areas where reasonably secureanchorage is obtainable for shipping, the tube meansassembly could beincorporated in a specially constructed salvage vessel. Such a vesselwould preferably have ballast tanks by means of which the vessel couldbe lowered in the water for greater stability. The tube means would beindependently suspended through a well formed in the salvage vesselshull, the well being located as close as possible to that point aboutwhich the vesselwould normally pivot to some extent while at anchor. Inthis manner, undesirable movement of the tube means would be obviated toa satisfactory degree.

It will be obvious that insofar as is possible, movement of the tubemeans in operation should beprecluded and since, as will later bedescribed, the tube means is provided with controllable buoyant supportmeans, motion of the salvage vessel will be dissimilar to that of thetube means and thus 'a rigid connection between the two is undesirable.

As best seen in FIGURE 2, the bottom end of the tube is preferablylocated as close to the bottom of the sunken vessel as possible tofacilitate dispersal of charges of buoyant'material 15 in the confinesof the ship and further to preclude insofar as possible prematurefouling of the tube exit.

The tube means comprises a plurality of tube sections of preferablyrectangular cross-section, although other sutiable cross-sections may beused, connected together by means such as flanged couplings and gasketssuch that a portion to be located under water may be sealed at will byvalve or gate means. The tube means includes a loading section 16 havinga loading hatch 17 through which the charges are inserted into the tubemeans. In addition, loading section 16 carries a ram deck 18 upon whichis mounted a motorized hoist 19 operable, through cable means 20 andpulley arrangement 21, to raise and lower a dead-weight plunger or Itshould be noted that the cross-sectional dimensions of the charges 15should be such as to just perrnit the charges to slide through the tubemeans without undue tilting relative to the longitudinal axis of saidtube means. In the drawings, the lateral dimensions of the charges areshown somewhat smaller in the interest of clarity.

Immediately below loading section 16 and connected in end to endrelation thereto is a buoyancy compensating means comprising awater-receiving tank section generally designated by numeral 23. Section23 comprises a tube 24 having the same internal dimensions as section 16and also having secured thereto in surrounding relationship an annularwater tank 25 for a purpose to be hereinafter described.

Coupled to the lower end of section 23 is a buoyant section generallydesignated by the numeral 26 and comprising a tube section 27 with abuoyancy tank 28 of any suitable configuration connected thereto insurrounding relationship. The function of the buoyancy section 26 is tosupport the tube means 10 in an operative stable position relative tothe loading deck 11 and the sunken vessel 14. In order to adjust thebuoyancy of the tank 28, to suit any particular circumstance orsituation, an air valve 29-and water valve 30 are provided. Air valve29fpermits blowing of the buoyancy tank by compressed air while watervalve 30 permits inflow of water to the buoyancy tank. Thus, by blowingcompressed air through air valve 29 and forcing water out of water valve30, or, by releasing air through air valve 29 and admitting waterthrough water valve 30, the buoyant force exerted by the tank 28 uponthe tube means may be readily and accurately controlled.

Below the buoyant section 26 is located a plurality of intermediate tubesections 31, the number required varying according to the depth of anygiven operation. The intermediate sections may be of any suitable,readily handled lengths and of course, have the same internal dimensionsand configuration as the other sections noted hereinbefore.

Coupled to the lowermost intermediate tube section, again by anysuitable well known tube coupling expedient, is a pump section 32comprising a tube member 33 to which is connected a submersible pump 34communicating with the interior of tube 33. Also connected to tube 33 isa flooding valve 35, the function of which will be hereinafterdescribed.

At its lower end, pump section 32 is slightly enlarged in cross-sectionto accommodate a pivoted gate member 36 operative to selectively closeoff or open the passage through pump section 32. The mechanism by whichthis gate 36 is operated may be one of many well known expedients. Inthe illustrated embodiment, the gate 36 is shown as being operated by ahydraulicram means 37 and 37, but, obviously, there are many other knownand suitable methods or expedients which could be used without departingfrom the spirit and scope of the invention herein disclosed. All that isrequired is a gate member which may be swung as desired from aninoperative position to a position positively sealing one portion of thepump section from another and, further, a gate member, which, in saidinoperative position, will in no way obstruct passage of charges 15through the pump section 32. In the embodiment shown, the gate 36 ispivoted at one end thereof to a fixed portion of the tube means as at3611. Hydraulic ram means 37 and 37' are pivotally mounted as at 37a toexterior surfaces of the tube means and the reciprocating pistonelements of the ram means are pivotally connected to pins 36' extendingfrom the gate through curved slots 32 in the enlarged portion of section32. Thus, on retracting the said piston elements, the gate 36 is forcedonto sealing engagement with gasket means to effectively seal the upperportion of the pump section from the lower portion thereof. Theoperation of pump section 32 will be understood as the descriptionproceeds.

The last section of the tube means 10 comprises a feed section 38 havingan enlarged portion 39 adjacent the upper end thereof for mounting someform of non-return means 40 within the tube means. This latter means asshown, includes a pair of complementary pivoted plates 41 and 42 biasedto normally lie in co-planar edge-abutting relationship to preventpassage of charges 15 upwardly into pump section 32. The abutting edgesof plates 41 and 42 are preferably serrated or castellated for matingregistration with one another.

Immediately above the non-return means 40 and secured to the innersurface of the feed section 38 is located a stop means 43 havinginternal dimensions of a size sufficient to permit the charges 15 topass therethrough and comprising two or more bar members connected tosaid inner surface. Further, the upper surface of stop means 43 istapered as at 44, to guide the charges through the stop means and thusfacilitate passage of said charges. The function of stop means 43 is toarrest or terminate the downward stroke of the dead-weight plunger 22.

The vertical distance between the plunger stop means 43 and thenon-return means 40 should be minimal to ensure that the plunger forcesall the charges past said non-return means. It will be obvious that ifeven one buoyant charge were to remain in the pump section, the

gate 36 would be unable to function properly and costly delays wouldarise.

To preclude any possibility of buoyant charges remaining in the pumpsection, the lower end of the plunger 22 is reduced such that thereduced portion 22a passes the stop means in ramming the buoyant chargesclear of the non-return means 40 and shoulder 22b abuts the stop meansto arrest further downward movement of the plunger.

After a sunken vessel has been located and all hatch- Ways and openingshave been suitably secured by means of perforate grid means, adaptorfunnels 13 are located and fixed in strategic positions in the deck orhull providing inlets to suitable compartments for the buoyant charges.The adaptor funnels 13 are preferably provided with non-return gate orvalve means 47 similar to the non-return means 40 and for the samepurpose. Further, abutment means 48 are adjustably connected to thelower end of feed section 38 to centre same with respect to the adaptorfunnel and to provide additional support to that obtained by thebuoyancy section.

The depth of the vessel is ascertained and the tube means is assembledaccordingly (FIGURE 1), the required number of intermediate sectionsbeing used to ensure that the bottom end of the feed section 38 isspaced from the bottom of the vessel a distance just sufiicient topermit the charges to leave the tube means and disperse within thecompartments of the sunken vessel.

The tube means is then positioned over an adaptor funnel 13 and thebuoyancy tank is flooded until the tube means sinks into the desiredposition, as best seen in FIG- URE 2, and the ratio of air to water inthe buoyancy tank is such as to substantially provide a state ofequilibrium such that the tube means is supported primarily by saidbuoyancy tank and to a slight degree by the adaptor funnel.

With the tube means assembled and in operative position, gate member 36is closed and flooding valve 35 is also closed. The submersible pump 34is then started and commences to pump water out of that portion of thetube means above the gate member 36 and into the water tank 25 throughline 45. The water pumped from the tube means is fed back into the watertank 25 in order to substantially maintain the equilibrium of thedevice.

As the upper portion of the tube means is being pumped out, charges ofsolid buoyant material having a specific gravity less than 1.0 andpreferably in the range of 0.2 to 0.1 are inserted in the tube meansthrough the loading hatch 17 such that when the water level reaches thesuction level of the pump 34, the upper portion of the tube means issubstantially full of buoyant material and the dead-weight plunger isthen lowered until it engages same. The flooding valve 35 is then openedand permits return of the water from water tank 25 to the tube meansabove gate member 36 through line 46 to substantially equalize pressureon opposing sides of the gate member 36 and facilitate opening thereofwith the result that the buoyant material is forced or rammed down thetube means by the plunger and ejected from the feed tube into thecompartment of the vessel. In order to ensure rapid return of the Waterfrom Water tank 25, air pressure is preferably applied to tank 25through a pipe P which may be connected to an air compressor aboard thesalvage vessel.

In instances where salvage operations are to be carried out inrelatively shallow waters, the dead-weight of the tube means may besustained by the sunken vessel since only a few sections will berequired to attain the necessary depth and in such instances, while thebuoyant section will still be effective to stabilize the tube means andwill be retained as part of the assembly, the water-receiving tanksection is not required. In short, there will be no necessity forbuoyancy compensating means during pumping of the tube means.

To ensure that the plunger 22 maintains a substantially *verticalattitude at all times during the ramming operation and' duringwithdrawal, the said plunger should be of a 6 length somewhat greaterthan the depth of the enlarged portion of pump section 32. In thismanner, the plunger will always be guided, at least in part, by the tubemeans and displacement from the vertical will be precluded to avoidjamming. The charges 15 must be of similar length for the same reason.

When the plunger 22 bears on the stop means 43 it is hoisted by means ofhoist 19 and the non-reutrn means 40 closes to preclude the possiblereturn of some of the buoyant material from the feed section of the tubemeans to the pump section where it would jam the operation of the gate36 as hereinbefore mentioned.

The foregoing cycle is then repeated, both at the same location and inthe other preselected locations until such time as the positive buoyancywithin the vessel is sufficient to overcome the dead-Weight thereofincluding any other forces tending to produce negative buoyancy. Duringthe cycling of the tube means, it may, in some cases, be found expedientto pump water into the compartments of the vessel to create turbulencetherein and to effect a more rapid and efiicient distribution of thebuoyant material, and further, in instances where ballast tanks areundamaged, it may sometimes be found feasible to blow such tanks bycompressed air means. 7

The buoyant material used may be one of several types such as theexpanded polyurethane plastics, cork, foamglass or the lighter woodssuch as cord-wood or undressed balsa logs. As will be well appreciatedby those skilled in the art, the only limiting factor of anysignificance to be considered in the choice of material would be thepressure conditions prevailing in any given salvage attempt.

Upon reaching that point in a salvage operation Wherein the vesselbegins to rise, the equipment may be readily withdrawn from the vesselmerely by reversing the insertion procedure that is, the buoyancy tankis blown as required, whereupon the apparatus or equipment rises, thelower portion of the tube means thus clearing the vessel which may thenascend under such control as is normally applied at this stage.

With respect to the means used in delivering the material through thetube means, namely the dead-Weight plunger, it is pointed out that otherexpedients such as chain-link or belt conveyors, compressed air orsimilar methods and apparatus could be used instead of that illustratedand described herein.

Many changes and modifications will be apparent to those skilled in thisfield a ter reading this disclosure without departing from the spiritand scope of the invention.

What I claim as new and Patent of the United States is:

1. In apparatus for use in the salvaging of a sunken vessel, thecombination comprising, tube means including tubular members secured inend to end engagement to extend from a surface structure to a locationwithin a sunken vessel; charge delivering means located at the upper endof said tube means operative to deliver preformed charges of buoyantmaterial down said tube means and into said sunken vessel; said tubularmembers including a pump section comprising a tube having a submersiblepump means attached thereto and communicating therewith, a gate memberpivotally mounted within said tube and operative to close said tube topermit the submersible pump to ptunp out water from a portion of thetube means above said gate member to facilitate loading of the preformedcharges into the tube means; controlled buoyancy means connected to saidtube means and operable to stabilize said tube means in submergedoperative position.

2. The combination as defined in claim 1 wherein said controlledbuoyancy means comprises a buoyant section, said buoyant sectioncomprising a further tube having secured thereto in surroundingrelationship a buoyancytank means, said last mentioned means having anair valve and a water valve therein operable to control the air to waterratio in said buoyancy tank such that the buoydesire to protect byLetters .duct the water pumped from said portion of the tube means tothe tank to substantially maintain the tube means in a state ofequilibrium.

4. The combination as defined in claim 3 and further including. pipemeans extending from said water-receiving tank to the said portion ofthe tube means, and com- 3 pressed air means selectively operable toforce the pumped water from the Water-receiving tank through said pipemeans and into said portion of the tube means to equalize pressure onopposite sides of the gate member.

5. The combination as defined in claim 1 wherein said gate member ispivotally mounted at one end thereof to an inner surface of said tube;hydraulic ram means including piston means, said hydraulic ram meansbeing pivotally mounted on the exterior of said tube and said pistonmeans being pivotally connected to pivot pins extending from the edgesof said gate member and projecting outwardly of the tube through curvedslots formed in said tube.

6. The combination as defined in claim 1 wherein said charge deliveringmeans comprises a dead-weight plunger;

Q 0 means mounted on said surface structure, operable to raise and lowersaid dead-weight plunger.

7. In apparatus for use in salvaging a sunken vessel, the combinationcomprising, tube means operable to extend from a surface structure to alocation within the sunken vessel; buoyant means operable to supportsaid tube means in operative location; sealing means in the tube meansand operable to seal off an upper portion of said tube means from alower portion thereof; pump means communicating with the upper portionof said tube 4 means and operable to remove water therefrom tofacilitate the loading of buoyant charges therein; buoyancy compensatingmeans adapted to maintain said tube means in substantial equilibriumduring pumping of the water from said upper portion of the tube means;charge delivery means located in operative relationship with said tubemeans to deliver buoyant charges through the tube means to the interiorof the sunken vessel.

References Cited by the Examiner UNITED STATES PATENTS 9/1962 Erickson114-54 MILTON BUCHLER, Primary Examiner.

ANDREW H. FARRELL, Examiner.

1. IN APPARATUS FOR USE IN THE SALVAGING OF A SUNKEN VESSEL, THECOMBINATION COMPRISING, TUBE MEANS INCLUDING TUBULAR MEMBERS SECURED INEND TO END ENGAGEMENT TO EXTEND FROM A SURFACE STRUCTURE TO A LOCATIONWITHIN A SUNKEN VESSEL; CHARGE DELIVERING MEANS LOCATED AT THE UPPER ENDOF SAID TUBE MEANS OPERATIVE TO DELIVER PREFORMED CHARGES OF BUOYANTMATERIAL DOWN SAID TUBE MEANS AND INTO SAID SUNKEN VESSEL; SAID TUBULARMEMBERS INCLUDING A PUMP SECTION COMPRISING A TUBE HAVING A SUBMERSIBLEPUMP MEANS ATTACHED THERETO AND COMMUNICATING THEREWITH, A GATE MEMBERPIVOTALLY MOUNTED WITHIN SAID TUBE AND OPERATIVE TO CLOSE SAID TUBE TOPERMIT THE SUBMERSIBLE PUMP TO PUMP OUT WATER FROM A PORTION OF THE TUBEMEANS ABOVE SAID GATE MEMBER TO FACILITATE LOADING OF THE PREFORMEDCHARGES INTO THE TUBE MEANS; CONTROLLED BUOY-